Have you EVER seen him come in one of our catchcan threads before? I know you are there all the time right with him/them, but look back at the post. I am in none on his threads, have asked time and again to please let us alone....so no, I will not go into his threads or interfere in any of his promotions, but this was started by the OP and our product and he came in and interfered. I didn't report it like I was told to do as I just want no more drama and no attacks direct or indirect.

On the subject, the catchcan is installed inline on the dirty side and the RX can has a one way checkvalve, so no oil can enter through reversion. All oil comes from the crankcase vapors.

If I'm using the wrong terminology, I apologize. The "reversion" I'm referring to can best be explained by this description I found online:

Quote:

Reversion is simply the exhaust gases momentarily flowing backwards during the overlap phase of the camshaft at low cycling rates. During the overlap phase the engine is on the exhaust stroke and the piston is pushing out the last of the exhaust gases. Prior to reaching top dead center the intake valve begins to open. At low cycling rates the intake charge and the exiting exhaust pulse have yet created any momentum. Thus the piston pushes some spent exhaust gas into the intake manifold.

I'm not talking about PCV gases or oil reversion, I'm saying there's combustion reversion coming back onto the intake valves directly from the cylinder, as described above, possibly causing some of the deposits.

I am thoroughly convinced all of the oil in my manifold came in via the PCV system, and not via reversion (as I'm defining it).

If I'm using the wrong terminology, I apologize. The "reversion" I'm referring to can best be explained by this description I found online:
I'm not talking about PCV gases or oil reversion, I'm saying there's combustion reversion coming back onto the intake valves directly from the cylinder, as described above, possibly causing some of the deposits.

I am thoroughly convinced all of the oil in my manifold came in via the PCV system, and not via reversion (as I'm defining it).

Reversion occurs with every engine and the severity depends on the cam profile and is worse at high RPM's. In fact, if you search, there is a youtube video from 8-9 years ago showing an F1 car at WOT on a dyno and the reversion cloud of fuel is 2-3" above the injection stacks.

Most are not aware that reversion is also why when a valve drops in one cylinder (or other part failure) you commonly see parts and damage in most others from the reversion pulse throwing pieces back and forth.

On the exhaust ports on our big alky motors (.800 plus lift cam) we mill in antireversion grooves around each port to minimize the effect. It is also why if you have a vacuum gauge on your car at idle and deceleration you will see 18-22" plus of vacuum, but at WOT zero.

Excellent observation, but it has no effect on valve coking as any measurable amount of fuel would actually reduce the coking issue (top tier fuels like Shell, etc. on a port injection engine keep valves looking like new for 100K plus miles where a DI engine has no fuel passing or touching the intake valves).

Now, if you had a oil burner with wore out cylinder bores and rings you could see oil pushed back to the intake valves and the IM from reversion....but were talking relatively new engines on this forum, and the proof that adding a proper can like the RX, SM, or Elite when new, you find zero, or near zero deposits of any kind on the valves.

The oil is easy to see where it originates from by just looking in any catchcan and seeing as it is installed inline from the crankcase to the intake manifold. If it stops the oil then no oil will be present in the intake manifold itself (easy to see with a LLT...remove the plenum). Remove the can and see it coat with oil again.

Seafoam treatment done yesterday. Lots of smoke, especially during the "spirited driving" afterward. It was embarrassing.

Followed the method for the LLT (posted here), but had to modify it a bit during the Deep Creep/Seafoam Spray step, as the LFX doesn't have the port that the DIY shows being used in the "Optional 2" step. Will post pics later of what I did as a workaround.

I did the full oil/gas/intake treatment, and will change oil probably tomorrow or the next day.

Tear down number 2: probably Saturday. Will take pics.

Also, going to investigate the layout of the IM a bit. I know it's got a divider between the two banks of intake runners, but I'm curious if it goes all the way to the back of the IM. If it's continuous from the TB to the rear of the IM, using the brake booster vacuum line to add Seafoam really probably only treats the driver's side bank of cylinders. If so, spraying the aerosol Seafoam from the front of the intake may be the only really effective way to clean the passenger side bank.

UPDATE: Further discussion of the layout of the IM and the effectiveness of using Seafoam via the brake booster vacuum line can be found in this post.

Oh, and I also sprayed my MAF sensor with some MAF cleaner while I was under the hood. Didn't look visibly dirty, but the electrodes are hard to see as they're contained in a housing with openings that aren't big enough for close inspection.

In addition, I'm adding a catch can. I like the RX check valve but I wish it had a neet-o multistage filter employing something like Elmer W. Bush's patent US 4089309 A or to a lesser degree the Mishimoto's 40 micron bronze filter.

In addition, I'm adding a catch can. I like the RX check valve but I wish it had a neet-o multistage filter employing something like Elmer W. Bush's patent US 4089309 A or to a lesser degree the Mishimoto's 40 micron bronze filter.

The newest Mishimoto is on the right track (expensive, but nice piece) but they are still allowing oil laden vapors to mix with separated ones so although they are getting close, they still have some pullthrough (The Elite works as well for 1/2 the $).

The little bronze 40 micron filter is off of a $15 lowes home air compressor separator.....but this is by far their best offering to date, and it would only take a small amount of redesign to make it as (or even...ahem...cough...better than) the RX can...but at a cost of 2-3 times as much.

The industrial applications for far more sophisticated versions have been in use for the past 30-40 years:

Warning: Thought experiment ahead. I have no scientific/engineering proof whatsoever.

It strikes me that if there are combustion by-products making their way back out to the intake valve area due to partially open intake valves during the exhaust purge that the same by-products would be sucked back into the cylinder on the next downstroke due to the vacuum created.

But if the intake valve area was "wet" with condensed oil vapor, then the combustion by-products would have something to stick to and would not ALL be sucked back in.

If true, this sounds like a perfectly vicious circle that would account for all the buildup AND support both positions of our learned co-contributors.

Also if true the solution would be to avoid the condensed oil vapors in the first place.

Lastly a chemical analysis of the oil in the catch can versus that captured from the walls of an intake port would speak volumes as to the relative contribution of each "source".

I think that analysis would certainly be definitive, but I'm not sure you're going to find someone willing to spend the time and money to collect and send the samples into someplace like Blackstone Labs to get it done. And I'm not sure what kind of sample quantity they require, so you may have problems getting adequate sample volume from the valves themselves. And lastly, I'm not sure that you wouldn't change the chemical content during the burning/coking process on the valves, which may make it impossible (or much more expensive) to match a source to the end product.

As for the rest of what you wrote about how combustion by-products sticking to the valves may increase accumulation of the PCV crud, it certainly passes the common sense test for me.

I have seen another article quoting a GM engineer stating this combustion "reversion" (as I'm calling it, right or wrong) as a source of the valve buildup, and other descriptions of manufacturers revising cam/valve timing in an attempt to mitigate the problem. But I can't deny what I saw (and photographed) in my own intake, and it was oily goo, not carbon from combustion, so I'm convinced the PCV system plays a role, too.

Then I slowly poured the other half into the brake booster vacuum line. It really helps to have a second person for this part to keep the RPMs up, as at idle RPM it's very easy to flood the engine and kill it. Several times. Ask me how I know!

Next, I wanted to do the Seafoam spray with the engine running, but as I said before, the LFX doesn't have the port they show being used in the LLT DIY, so I had to improvise. First, I thought I could just use the included curved plastic guide and just slip it between the intake air tube and the throttle body, but the TB plate is so close to the top/front of the opening that I felt the guide and spray tube would actually make contact with it if it opened during the process.

So, I started trying to figure out how else to route the spray tube into a position upstream of the TB where it could spray into the intake air stream, and came up with this:

I wound up using the curved guide near the end of the spray tube, and pulled the spray tube back through the intake tube until it was routed within the intake tube roughly like this:

This seemed to work pretty well, but there was a good coating of Seafoam in most of the intake air tube when I was done, and some pooling of Seafoam near the TB. This left an oily residue in the intake tube, which I'm not thrilled about, but short of removing the tube completely and simply spraying into the bare TB, I'm not sure what else to do.

Again, it would have been nice to have an assistant for this step, as I killed my motor a couple of times during it due to low RPMs. Seafoam recommends spraying it in with the RPMs about 1000 above idle, BTW.

Finally, I poured a full can in my gas tank and filled it up. Maybe not necessary, but WTF, I had a can so I went for the full Monty.

I think that analysis would certainly be definitive, but I'm not sure you're going to find someone willing to spend the time and money to collect and send the samples into someplace like Blackstone Labs to get it done. And I'm not sure what kind of sample quantity they require, so you may have problems getting adequate sample volume from the valves themselves. And lastly, I'm not sure that you wouldn't change the chemical content during the burning/coking process on the valves, which may make it impossible (or much more expensive) to match a source to the end product.

Your analysis is correct.

In retrospect I think a simpler (and less accurate) test would be to take a small amount of the wet valve area buildup and compare it with a similar small amount of oil from the catch can. A color analysis of the two samples might answer the question IF there is a noticeable difference.